Project Summary This Fast Track SBIR project long term objective is to develop and test of a minimum viable product (MVP) of The Oaks, a perioperative, digital, education, assessment and guided exercise software application for adults with osteoarthritis of the knee (KOA) awaiting total knee replacement (TKR) surgery. This product is relevant to the mission of the NIA because it addresses the call for ?Development of technologies to assist in the improvement of physical function and mobility in older persons prior to (prehabilitaiton) or following (rehabilitation) elective/ planed surgery?. The envisioned MVP is an elegantly simple mobile application that is designed to specifically measure the Centers for Medicare/Medicaid's (CMS) Comprehensive Care for Joint Replacement (CJR) required assessments and physical performance assessments prior to and following TKR, provide educational content typically contained in pre-operative TKR classes and track recovery of function for 30 days following TKR surgery. This product was conceived in response to four main drivers: 1) the growing number of adults aging with KOA needing TKR, 2) the need for developing improved patient care perioperatively for TKR surgeries, 3) the finding that attending educational classes and performing strengthening exercises prior to TKR improves outcomes and lowers post surgical medical utilization potentially saving billions of dollars and 4) the CMS CJR rule requiring healthcare systems to reduce the cost of care delivery for TKR surgeries, within a diminishing bundled payment. This application is very timely and has great potential for widespread adoption, as it will be designed based on end user feedback, from all stakeholder groups including people with KOA and the medical care team. Broad Objective: We intend to translate existing evidence-based educational material, assessments and exercises to a mobile device for widespread dissemination and adoption to prevent functional decline pre and post operatively, promote health and wellbeing and improve patient care and outcomes through coordinated higher quality of care. Approach: In Phase I we will 1) employ user-centered design methodologies to develop a minimum viable product (MVP) Alpha version of The Oaks for adults over age 60 with TKR surgery and 2) identify and evaluate feature and content expansions/adaptations for The Oaks Beta MVP. In Phase II we will 1) employ user-centered, iterative design approaches to develop The Oaks Beta MVP and we will 2) complete feasibility, usability, and a pilot effectiveness study. Research Design: We will use a between subjects 1-way ANOVA, (App/No-App) repeated measures (pre/post-surgery) design to determine feasibility, usability and effectiveness (pilot data) of The Oaks. Participants will self-select class/no-class and then be randomized to App (Group 1) or No-app (Group 2) stratified by class/no class. Expected Outcomes: We believe that The Oaks will be a feasible and usable adjunct to TKR for KOA perioperatively and for 30 days post surgery. The app will provide healthcare professionals with important data regarding function while reducing the cost of care delivery.